Hebrews 5:1, 3, 6, 10, 12

For every high priest taken from among men is ordained for men in things pertaining to God, that he may offer both gifts and sacrifices for sins

And by reason hereof he ought, as for the people, so also for himself, to offer for sins.

As he saith also in another place, Thou art a priest for ever After the order of Melchisedec.

called of God an high priest after the order of Melchisedec.

For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God; and are become such as have need of milk, and not of strong meat.